firejail-handler-bittorrent-ctl

#!/bin/sh
#
## BitTorrent URL handler for Firejail
#+ (1) inside the sandbox `firejail-handler-bittorrent` drops a URL
#+ at a read/write accessible location
#+ (2) outside the sandbox this script picks up the URL and starts
#+ a fully sandboxed bittorrent application
#+ (defaults to a local transmission-daemon)

# shellcheck disable=SC2034

### vars
## source common settings
_settings_file="firejail-handler-settings-extra.inc"
if [ -f "${HOME}/.config/firejail/${_settings_file}" ]; then
    #+ use settings defined by user
    . "${HOME}/.config/firejail/${_settings_file}"
elif [ -f "/etc/firejail/${_settings_file}" ]; then
    #+ use system-wide settings
    . "/etc/firejail/${_settings_file}"
else
    #+ fall back to hard-coded values
    if [ "$(which xdg-user-dir)" ]; then
	_drop_dir="$(xdg-user-dir DOWNLOAD)"
    else
	_xdg_config_home="$(env | grep -c "XDG_CONFIG_HOME")"
	if [ "$_xdg_config_home" = 1 ]; then
	    if [ -s "${XDG_CONFIG_HOME}/user-dirs.dirs" ]; then
		_drop_dir="$(grep "^XDG_DOWNLOAD_DIR=" "${XDG_CONFIG_HOME}/user-dirs.dirs" | awk '{split($0,a,"="); print a[2]}' | sed 's/"//g')"
	    fi
	elif [ -s "${HOME}/.config/user-dirs.dirs" ]; then
	    _drop_dir="$(grep "^XDG_DOWNLOAD_DIR=" "${HOME}/.config/user-dirs.dirs" | awk '{split($0,a,"="); print a[2]}' | sed 's/"//g')"
	else
	    _drop_dir="${HOME}/Downloads"
	fi
    fi
    # bittorrent client watch dir for .torrent files
    _download_dir="$_drop_dir"
    ## drop dir location where the URL data will be saved temporarily
    #+ IMPORTANT: this needs to be read/write accessible in the sandbox
    _drop_dir="${_drop_dir}/.firejail-dropzone"
    ## protocol handlers
    #+ bittorrent
    _drop_file_bt="${_drop_dir}/bittorrent.drop"
    _media_dl_mode="local"
    _rpc_bin="/usr/local/bin/transmission-remote"
    _rpc_port_local="9091"
    _rpc_port_tunnel="9999"
    _sshfs_mountpoint="/mnt/sshfs-remote"
    _systemd_service="transmission-daemon"
    #+ youtube
    _drop_file_yt="${_drop_dir}/youtube.drop"
    _media_player_bin="/usr/local/bin/mpv"
fi

_selfie="$(basename "$0")"


### logic
# ensure drop location exists
[ ! -d "$_drop_dir" ] && mkdir -p "$_drop_dir"

# ensure needed commands are available
if [ ! -x "/usr/bin/inotifywait" ]; then
    echo "Command not found: /usr/bin/inotifywait - aborting"
	exit 1
fi
if [ ! -x "$_rpc_bin" ]; then
    echo "Command not found: ${_cmd} - aborting"
	exit 1
fi

## watch drop location
[ -e "$_drop_file_bt" ] && rm -f "$_drop_file_bt"
touch "$_drop_file_bt"
inotifywait -m -e modify --format '%f' "$_drop_file_bt" | while read -r line
do
    if [ -s "$_drop_file_bt" ]; then
	    #+ get bittorrent data
        _bt_data="$(head -n 1 "$_drop_file_bt")"
        _drop_is_magnet="$(grep -cf "^magnet" "$_drop_file_bt")"
        _drop_is_torrent_file="$(grep -cf "\.torrent" "$_drop_file_bt")"
        if [ "$_drop_is_magnet" != 0 ]; then
            #+ we have a magnet link
            # add magnet
            "$_rpc_bin" "$_rpc_port" -a "$_bt_data" > /dev/null 2>&1 &
            # notify user
            if [ -x "/usr/bin/notify-send" ]; then
                _bt_name="$(echo "$_bt_data" | awk '{split($0,a,"&"); print a[2]}' | sed "s|dn=||" | sed "s|+| |g" | sed "s|%27|\'|g")"
                notify-send "Firejail :: BT handler" "Magnet added\\n${_bt_name}" &
            fi
        elif [ "$_drop_is_torrent_file" != 0 ]; then
            #+ we have a .torrent file
            # add .torrent
            # moved into the configured watch dir, nothing else to do here
            # notify user
            if [ -x "/usr/bin/notify-send" ]; then
                _bt_name="$(echo "$_bt_data" | sed "s/.torrent//")"
                notify-send "Firejail :: BT handler" "Torrent added\\n${_bt_name}" &
            fi
        else
            #+ assume error
            # notify user
            if [ -x "/usr/bin/notify-send" ]; then
                notify-send "Firejail :: BT handler" "ERROR processing link [${_selfie}]" &
            fi
        fi
        # reset
        truncate -s 0 "$_drop_file_bt" &
    fi
done

exit 0